The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 16-35mm F2.8L III and the Canon 16-35mm f2.8L USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon 16-35mm F2.8L III is the longer of the two lenses at 128mm. The Canon 16-35mm f2.8L USM with a length of 103mm, is 25mm shorter. Besides being longer, the Canon 16-35mm F2.8L III also has a larger diameter of 89mm compared to the Canon 16-35mm f2.8L USM's 84mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Canon 16-35mm f2.8L USM weighs 600g, 24% (190g) lighter than the Canon 16-35mm F2.8L III's weight of 790g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Wideangle Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon 16-35mm F2.8L III and the Canon 16-35mm f2.8L USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Focal Range
Both lenses have the same focal range of 16-35mm and the fastest aperture of F2.8.